title: Immunoprotection of mice against Schistosomiasis mansoni using solubilized membrane antigens.
abstract: BACKGROUND
  Schistosomiasis continues to be one of the most prevalent parasitic diseases in the world. Despite the existence of a highly effective antischistosome drug, the disease is spreading into new areas, and national control programs do not arrive to complete their tasks particularly in low endemic areas. The availability of a vaccine could represent an additional component to chemotherapy. Experimental vaccination studies are however necessary to identify parasite molecules that would serve as vaccine candidates. In the present work, C57BL/6 female mice were subcutaneously immunized with an n-butanol extract of the adult worm particulate membranous fraction (AWBE) and its protective effect against a S. mansoni challenge infection was evaluated.
  
  
  RESULTS
  Water-saturated n-butanol release into the aqueous phase a set of membrane-associated (glyco)proteins that are variably recognized by antibodies in schistosome-infected patients; among the previously identified AWBE antigens there is Alkaline Phosphatase (SmAP) which has been associated with resistance to the infection in mice. As compared to control, a significantly lower number of perfuse parasites was obtained in the immunized/challenged mouse group (P<0.05, t test); and consequently, a lower number of eggs and granulomas (with reduced sizes), overall decreasing pathology. Immunized mice produced high levels of sera anti-AWBE IgG recognizing antigens of ∼190-, 130-, 98-, 47-, 28-23, 14-, and 9-kDa. The ∼130-kDa band (the AP dimer) exhibited in situ SmAP activity after addition of AP substrate and the activity was not apparently inhibited by host antibodies. A preliminary proteomic analysis of the 25-, 27-, and 28-kDa bands in the immunodominant 28-23 kDa region suggested that they are composed of actin.
  
  
  CONCLUSIONS
  Immunization with AWBE induced the production of specific antibodies to various adult worm membrane molecules (including AP) and a partial (43%) protection against a challenging S. mansoni infection by mechanism(s) that still has to be elucidated.
authors.affiliation: Unidad de Trematodiasis, Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
authors.forename: Guidenn
authors.initials: G
authors.lastname: Sulbarán
authors.forename: Oscar
authors.initials: O
authors.lastname: Noya
authors.forename: Beatríz
authors.initials: B
authors.lastname: Brito
authors.forename: Diana E
authors.initials: DE
authors.lastname: Ballén
authors.forename: Italo M
authors.initials: IM
authors.lastname: Cesari
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000947:Antigens, Helminth / Q000008:administration & dosage / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D007279:Injections, Subcutaneous; D051379:Mice; D008810:Mice, Inbred C57BL; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000276:immunology / Q000517:prevention & control*; D014611:Vaccination / Q000379:methods*
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth